1. CN101592317A, entitled “Outdoor Surface-mounted LED lamp Housing Material”, comprising epoxy resin, antistatic agents and ultraviolet resistance material. It further includes light stabilizers. However, the material has deficiencies. First, the lights fail and get damaged due to the water penetration, caused by epoxy resin and silicone being immersed in a high humidity environment or water for a long time, and the materials are not waterproof over the long term. Second, the epoxy resin and the silicone become yellow, cracked and the housing detaches, resulting in steam entering into the light source and rendering the light source ineffective.
2. CN102454908A, entitled “Exposed Waterproof LED lamp string and Manufacturing Method Thereof”, combines LED lamps, PCD circuit board, and anti-ultraviolet PU leads together and then cures under the high temperature of 50-60° C. This disclosure solves the problems of secure connection between modified epoxy resin and PVC cables, and the waterproof treatment. In the practices, several perforated lamps are connected together in parallel in accordance with a certain rule. Each perforated lamp includes a LED bead, a circuit board, a rubber sleeve and leads. The structure and arrangement are described as below: 1) The LED bead is located at the top of the perforated light; 2) the circuit board includes a control circuit electrically connected to the LED bead, for controlling the LED bead; 3) the external power supply is connected to the control circuit by the leads; 4) the sleeve is cylindrical and filled with waterproof glue, and the LED bead, circuit board and the connection between the leads and the circuit board are encased in the sleeve.
3. CN202432299U, entitled “A Waterproof LED Line Source”, includes a mounting aluminum frame, a PC tube connected to the mounting aluminum frame, a PCB board located within the PC tube, multiple LED lamps located on the PCB board and two plugs provided at the two ends of the mounting aluminum frame. The PCB board is filled and sealed with epoxy resin, silicone is provided on the connections among mounting aluminum frame, PC tube, PCB board and the plugs, and all the edges of the LED line source are also sealed with the silicone.
The deficiencies of these prior arts are illustrated as below: first, the lights fail and get damaged due to the water penetration, caused by epoxy resin and silicone not being water proof in the long term and being immersed in a high humidity environment or water for a long time; second, the epoxy resin and the silicone become yellow, and cracked and the housing detaches, resulting in steam entering into the light source, rendering the light source ineffective.
4. CN102628562A, entitled “LED light Bar with a fully waterproof filling and sealing structure and Manufacturing Method Thereof” discloses a LED light bar body (1); and an extruded fully waterproof filling and sealing structure (2) encircling along the LED light bar body (1). The disclosure also discloses a filling and sealing method of a LED light bar, including: providing a LED light bar body (1); extruding and molding the silicone material on the LED light bar body (1) by the extrusion process, to form an extruded fully waterproof filling and sealing structure encircling along the LED light bar body (1). The waterproof extrusion material for extruding the LED light bar in the extrusion process is preferably PVC, TPU or the combination of PVC and TPU. These extrusion materials are not only used for extruding and molding to fit the contour of the LED light bar, but also have good heat dissipation, light transmission and weather resistance, which is especially suitable for encasing the LED light bar to ensure the good light transmission of the LED light bar. Therefore, the waterproof filling and sealing structure made of by these extrusion materials does not affect the normal work, light emitting and heat dissipation. The deficiency of this prior art is because of the different properties of the two materials. PVC, TPU or the combination of PVC and TPU is adopted in the extrusion process to manufacture the LED light bar, and the waterproof filling material is used for sealing. The thermal expansion and contraction coefficients of these two materials are different. When used outdoors or immersed in a high humidity environment or water for a long time, there would be water penetration, which leads to the lamp failing, getting damaged, and becoming yellow, or cracked and the housing detaches, rendering the light source ineffective.